With the rapid development in display technology, display devices with touch function are getting more and more popular because of the advantages such as visualization. Based on the position of the touch panel relative to the display panel, existing display devices can generally be divided into two types, i.e. on cell touch panel and in cell touch panel. Compared to the on cell touch panel, the in cell touch panel has a thinner thickness and higher light transmittance, and therefore has a wider application range.
For the current display devices, as a current light emitting device, the organic light emitting diode (OLED) is increasingly used in the field of high-performance display due to its characteristics of self-illumination, fast response, wide viewing angle, and being able to be produced on flexible substrates. OLED display devices can be divided into PMOLED (Passive Matrix driving OLED) and AMOLED (Active Matrix driving OLED) according to the driving mode. The AMOLED display device is expected to replace LCD (Liquid Crystal Display) as the next generation of new flat panel display device due its advantages of low manufacturing cost, high response speed, low power consumption, being DC driving for portable devices, large operating temperature range and so on. Therefore, AMOLED display panel with in cell touch function are more and more popular.
In the current AMOLED display panel, each OLED is driven to emit light by the driving circuit formed by a plurality of TFT (Thin Film Transistor) within the same pixel unit as the OLED located on the array substrate, so as to implement display. The in cell touch screen panel (TSP) is also formed by manufacturing the sensor and the driving circuit for sensing a touch in each pixel unit of the array substrate using the array process. If the sensor and the driving circuit of the TSP are superimposed in the AMOLED pixel unit, then a number of TFTs used as the driving circuit for sensing touch shall be added in addition to the original TFTs forming the driving circuit for display in the pixel unit, such that a certain space of the pixel unit will be additionally occupied. The free space in the pixel unit is limited, therefore the concurrent manufacture of the in cell touch panel and the AMOLED driving circuit is greatly limited, the producing difficulty is enhanced and the product quality is reduced.